Myriad approaches have been pursued to control pests. Many of these methods and compositions are directed to the control of pests that attack plants, most notably commercially valuable plants. Although much current agricultural research has pest control as its objective, pest destruction of plants and plant products is still a major problem.
Control of pests of plants, livestock, and households has been accomplished with the aid of chemical and biological control agents. Unfortunately, approaches using these agents may fail due to inadequate formulation of the pesticides. In particular, many formulations are adversely affected by major environmental hindrances. By way of example, rainfall can wash away control agent deposits and sunlight can inactivate the active agent.
Starch and flour have been studied extensively (McGuire and Shasha, 1990; U.S. patent applications Ser. Nos. 07/730,763 and 07/913,565, the disclosures of which are incorporated herein by reference) as materials to encapsulate pesticides. Most of this work has been done with granular matrices in efforts to reduce the amount of chemical pesticide needed to control pests or to protect environmentally sensitive pesticides (usually biological control agents) and thus extend their activity. While efforts with these granular formulations have been successful, by far, the majority of pesticides are applied as sprayable formulations. Shasha and McGuire disclose such a sprayable formulation for microbial insecticides consisting of a mixture of cornstarch or flour and sucrose. This formulation enhances and extends the performance of the active agents (U.S. pat. No. 5,061,697). Formulations of this type are essential for the widespread use of biological control agents and for enabling the reduction of potentially environmentally hazardous chemical pesticides. Formulations that are effective with lower active ingredient rates are possible through the judicious use of protectants, attractants, or other additives that synergize ingredient activity.
However, these formulations require additives at solids rates of 2 to 6% of the spray volume. These formulations, therefore are most useful under low spray volume conditions.
The present invention utilizes a product other than starch to produce a film upon spraying and is distinct from previous technology. While other products from farm commodities have been used as carriers in granular formulations, little work has yet been done with these products for sprayable formulations. For example, wheat gluten has extensively been used in the baking industry but has never before been tested as a pesticide formulation ingredient. Our tests with gluten-based formulations suggest a significant improvement over existing technology because solids rates of a maximum of 1% show improved rainfastness and survival of the active agent. These types of solids rates should extend the usefulness of the formulation to a wider range of spray systems.